<template>
  <div>
    <button type="button" v-on:click="selectFile()" class="btn btn-white btn-default btn-round">
      <i class="ace-icon fa fa-upload"></i>
      {{text}}
    </button>
    <input class="hidden" type="file" ref="file" v-on:change="uploadFile()" v-bind:id="inputId+'-input'">
  </div>
</template>

<script>
  export default {
    name: 'big-file',
    props: {
      text:{
        default: "上传大文件"
      },
      inputId: {
        default: "file-upload"
      },
      suffixs: {
        default: []
      },
      shardSize: {
        default: 50 * 1024
      },
      url: {
        default: "oss-append"
      },
      use: {
        default: ""
      },
      afterUpload: {
        type: Function,
        default: null
      },
    },
    data: function () {
      return {
      }
    },
    methods: {
       uploadFile(){
        let _this = this;
        let formData = new window.FormData();
        let file = _this.$refs.file.files[0];

        console.log(JSON.stringify(file));

        let key = hex_md5(file.name + file.size + file.type);
        let key10 = parseInt(key,16);
        let key62 = Tool._10to62(key10);
        console.log(key,key10,key62);


        //  判断文件格式
        let suffixs = _this.suffixs;
        let fileName = file.name;
        let suffix = fileName.substring(fileName.lastIndexOf(".") + 1, fileName.length).toLowerCase();
        let validateSuffix = false;
        for (let i = 0; i < suffixs.length; i++){
          if (suffixs[i].toLowerCase() === suffix){
            validateSuffix = true;
            break;
          }
        }

        if (!validateSuffix){
          Toast.warning("文件格式不正确！只支持上传：" + suffixs.join(","));
          $("#" + _this.inputId + "-input").val("");
          return;
        }

        //  文件分片11
        let shardSize = _this.shardSize ; //以20M为一个分片
        let shardIndex = 1; //  分片索引  1 表示第一个分片
        let size = file.size;
        let shardTotal = Math.ceil(size / shardSize); //  总片数

        let param = {
          'shardIndex': shardIndex,
          'shardSize': shardSize,
          'shardTotal': shardTotal,
          'use': _this.use,
          'name': file.name,
          'suffix': suffix,
          'size': file.size,
          'key':  key62
        };

        _this.check(param);
      },

      /**
       * 检查文件状态，是否已上传过？传到第几个分片
       * @param param
       */
      check(param){
        let _this = this;
        _this.$ajax.get(process.env.VUE_APP_SERVER + '/file/admin/check/' + param.key).then((response)=>{
          let resp = response.data;
          if (resp.success){
            let obj = resp.content;
            if (!obj){
              param.shardIndex = 1;
              console.log("没有找到文件记录，从分片1开始上传");
              _this.upload(param);
            }else if(obj.shardIndex === obj.shardTotal){
                //  已上传分片 = 分片总数 说明已上传完成，不要重新上传
              Toast.success("文件极速秒传成功！");
              _this.afterUpload(resp);
              $("#" + _this.inputId + "-input").val("");
            }else{
              param.shardIndex = obj.shardIndex + 1;
              console.log("找到文件记录，从分片" + param.shardIndex+ "开始上传");
              _this.upload(param);
            }
          }else{
            Toast.error("文件上传失败");
            $("#" + _this.inputId + "-input").val("");
          }
        })
      },

      upload: function (param) {
         let _this = this;
         let shardIndex = param.shardIndex;
         let shardTotal = param.shardTotal;
         let shardSize = param.shardSize;
        let fileShard = _this.getFileShard(shardIndex, shardSize);
        //  将图片转为base64进行传输
        let fileReader = new FileReader();
        Progress.show(parseInt((shardIndex - 1) * 100 / shardTotal));
        fileReader.onload = function (e) {
          let base64 = e.target.result;
          param.shard = base64;

          _this.$ajax.post(process.env.VUE_APP_SERVER + '/file/admin/' + _this.url, param).then((response) => {
            Loading.hide();
            let resp = response.data;
            console.log("上传文件成功：", resp);
            Progress.show(parseInt((shardIndex) * 100 / shardTotal));
            if (shardIndex < shardTotal){
              //  上传下一个分片
              param.shardIndex = param.shardIndex + 1;
              _this.upload(param);
            }else{
              Progress.hide();
              _this.afterUpload(resp);
              $("#" + _this.inputId + "-input").val("");
            }
          });
        };
        fileReader.readAsDataURL(fileShard);
      },

      getFileShard: function (shardIndex, shardSize) {
         let _this = this;
        let file = _this.$refs.file.files[0];
        let start = (shardIndex - 1) * shardSize; //  当前分片起始位置
        let end = Math.min(file.size, start + shardSize); //  当前分片结束位置
        let fileShard = file.slice(start, end);  //  从文件中截取当前的分片数据
        return fileShard;
      },
      selectFile(){
        let _this = this;
        $("#" + _this.inputId + "-input").trigger("click");
      }
    }
  }
</script>
